In residential and commercial settings, the cleaning of air prior to heating or cooling same has become increasingly important. More specifically, consumers desire improved air filtration due to an increase in allergy symptoms often caused by dust, pollen, and pet dander to name a few, and due to the likelihood of other more dangerous airborne contaminants. Further, the use of modern construction methods which tightly seal homes and other structures in order to improve energy efficiency necessarily results in less air flow from outside the structure and more recirculation of existing air within the structure. Thus, any airborne contaminants present within the structure must be eliminated from the air prior to recirculation.
Traditionally, air filters for heating and cooling systems have been provided in a frame having fixed dimensions which typically correspond to particular heating and cooling system size requirements. Because the size requirements are fixed, retailers must carry a large number of sizes in order to accommodate needs of the buyers. This large number of air filters which must be kept on hand thus necessitates a large amount of storage and shelf space within the store. As a result of the above, air filters which are adjustable by the user were developed.
One example of an adjustable air filter is disclosed in U.S. Pat. No. 5,476,526. The air filter shown in the '526 patent includes an outer frame constructed of channel members which are movable relative to one another to allow adjustment of the frame in both the width and length dimensions. The frame holds a filter member centered between two opposed grids in sandwich fashion. To assemble the air filter, the user determines the filter size for the particular heating or cooling unit and cuts the filter member to the appropriate length and width. Once the filter member is sized, the user then trims the front and rear grids to correspond to the filter size, and the filter member is placed between the two grids. The size of the outer frame is then adjusted by sliding the channel members relative to one another, and the user-sized grid-filter sandwich is assembled into the frame.
U.S. Pat. No. 5,087,276 also discloses a user-sizable furnace filter. This filter arrangement includes a carton defining templates thereon which are used for sizing the filter member and frame. The filter element is first sized by placing same on the paper template, and the filter element is then trimmed to the appropriate length and width. The frame is constructed of channels or right angle members, and the size of the frame is adjusted by slidably engaging the right angle members with one another, and then placing same on the frame template. The width and length of the frame is adjusted by sliding the channels relative to one another to the appropriate size to match the filter element. The filter element is then assembled within the frame.
While the above filter arrangements conveniently allow user-sizing, the arrangements involve many assembly steps, which necessarily complicates the sizing procedure for the end user. Further, the multiple components required for the above arrangements also increases manufacturing costs and also complicates assembly.
In an effort to obviate or at least minimize the above disadvantages associated with conventional filter designs, the air filter arrangement according to the invention includes a filter frame and a filtration member secured within the frame, which frame and filtration member which are selectively sizable by the user or the manufacturer to any one of a number of standard sizes. The frame is advantageously constructed of a pair of frame components or frame halves which in the preferred embodiment are removably secured to one another by a locking arrangement. The filtration member is sandwiched between these frame components and secured therebetween by the locking arrangement. For the convenience of the user, the frame defines thereon guides disposed in predetermined locations to correspond to the standard sizes most commonly required in heating and cooling systems, which guides serve as cutting guides to allow the user to easily and quickly cut the filter arrangement to the correct size. Further, the filter arrangement according to the invention is simple to size, since the frame and filtration member are cut to size in one step.
The locking arrangement according to the invention is releasable and thus permits reuse of the filter frame when the filtration member has become saturated and replacement or cleaning is necessary. More specifically, when replacement of the filtration member is necessary, the frame components are pulled apart from one another to release the filtration member, the filtration member is either cleaned or disposed of, and the clean filtration member or a new filtration member is placed between the frame components which are then locked together to securely position the filtration member therebetween. While a releasable locking arrangement is desirable primarily to allow reuse of the frame for environmental purposes, it will be appreciated that other locking arrangements are within the scope of the invention. For example, the opposed frame components can be permanently secured to one another through plastic welds, adhesive, or staples, for example.
The plastic filter frame pursuant to the invention is advantageously formed from a sheet-like plastic material by vacuum molding, which is a relatively inexpensive process, and also results in a frame which is sufficiently rigid, but also lightweight and very thin, which effectively reduces material and manufacturing costs.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.